Smoke Alarm or CO2 Alarm Batteries

As a Home Watch caretaker provider, we are changing batteries in smoke detectors and CO2 detectors almost monthly at one home or another for our customers. Home Watch providers have ladders, love to get exercise, and they really hate that beeping. Doesn’t everyone? 🙂 We always perform the below Home Watch Best Practices for Smoke detectors and CO2 detectors in our customers homes and they always agree with our recommendations.

We thought it would be useful to anyone to know some of the basics about these lifesaving devices so we wanted to share our simple knowledge of them.

First off, there are a ton of different models on the market, so, unfortunately, there is no blanket statement to cover them all. We’ll just list some info that applies to most of them understanding that yours may be different.

Types of Batteries
5 types of batteries have been seen in these units:

• Regular 9 volt battery (most common)
• U9VL-X (10 year Ultra Life 9 volt)
• 123A Lithium battery (more common, 10 year, long life)
• AA batteries (old units, uncommon)
• AAA batteries (old units, uncommon)

Replacement Cycle for Batteries

• It is a common best practice to replace ALL batteries as soon as one starts beeping as the life of the others will then be nearing the end. Unless you want to be hearing a chirping at 3am that you will have to get up and fix or not sleep, replacing them all on the same cycle generally means they’ll all need replacement around the same time! Who knew, right?

Battery only versus Battery Backup

• If your smoke alarm has wires coming from the ceiling (generally a 3 pin prong on detector), this means it runs on electrical from the home and the battery in the unit is actually a battery backup for when power is out.

Detector Unit Replacement

• The industry actually recommends replacing each and every detector every 5 years. The reason being that the detector intake (where it samples air from for readings) will eventually get a layer of grime from the normally occurring air in the home and this will stop it from being 100% accurate in reading and ability. If you cook foods indoors that produce smoke or if you fry or use grease in the kitchen this too will add to the coating. We have seen one of our own rental properties need to be stain-blocked (Kilz primer) because of the layer of grease from smoke that built up from 3 years of heavy frying. It’s worse with cigarette smokers as that produces a yellow layer of nicotine buildup. Replace every 5 to be safe.

Final Thoughts:

• When shopping for a new device, don’t go high, and don’t go low. We like a mid-range priced unit that provides good, basic features and doesn’t have much for “bells and whistles.” Remember you’re going to throw them away in 5 years. Save your money. Your money is best spent on effective basic service (smoke detection/CO2 etc).
• Do not bother with the expensive 10 year, ultralife batteries. Why buy a 10 year battery when you’re going to replace the entire unit in 5 years? You wouldn’t put old batteries in a new unit (I wouldn’t…and most say not to in the instructions), so just save your money. They’re NOT cheap…but regular 9V batteries are.
• Whenever possible, make sure you have a combination of both CO2 and Smoke detectors, especially anywhere you will sleep which includes a favorite nap couch, tv room, and most certainly bedrooms.
• If your home was wired for detectors, always use and reconnect the home wiring. We don’t really feel like the home wiring provides any longer life for the batteries as they seem to require replacement at about the same rate, but it’s a 2nd line of defense against power loss to the device which would render is completely useless.

Thanks for reading.